Fundamentals of Exercise for
Nutrition
By Jennifer Turley and Joan Thompson
© 2016 Cengage
Presentation Overview
• Fuel and Utilization During Exercise
• Carbohydrates
– Carbohydrates in the Body and Diet
– Carbohydrate Management for Enhanced Exercise Performance
– Recovery Nutrition after Exercise
• Proteins
– Proteins in the Body and Diet
– Protein Management for Enhanced Exercise Performance
• Fats
– Fats in the Body and Diet
– Fat Management for Enhanced Exercise Performance
• Thermal Regulation and Hydration
– Understanding and Controlling Body Temperature
– Dehydration to Hydration
Fuel Utilization During Exercise
• ATP production is primarily from carbohydrate and
fat
• As the intensity of the exercise increases, the
percent of carbohydrates used to produce ATP
increases
• Nutrition supplies the substrate or fuel
(carbohydrate, fat and protein) and the essential
structural components of enzymes (cofactors)
needed to drive chemical reactions to generate
ATP through:
– Glycolysis
– The citric acid cycle
– The electron transport chain.
ATP Energy Production through Glycolysis, the Citric
Acid Cycle, and the Electron Transport Chain
Carbohydrates
• The objectives of dietary
carbohydrate management is to
maintain blood sugar and replete
muscle glycogen
• Carbohydrate as fuel supports high
intensity exercise
• Carbohydrate are limited in the body
Carbohydrates in the
Body and Diet
• Blood Glucose
– 4.5 grams of glucose total
– Constantly used by RBC and CNS
• Liver Glycogen
– 75 (to 100) grams when repleted
– Used to maintain blood glucose
• Muscle Glycogen
– Amount of exercise and dietary
carbohydrate intake determines the amount
– Used to produce ATP in the muscle during
exercise
Carbohydrate Management for
Enhanced Exercise Performance
• Diet and exercise influence glycogen stores in
the muscle.
– High carbohydrate intake (7-10 gm/Kg/day)
– 60-65% of Calories from carbohydrate
• The timing of the carbohydrate intake in
relation to exercise is important:
– Prior to the Exercise (4 hours before or 2 hours
before and 5-10 minutes before)
– During the Exercise (about every 15 or 20
minutes)
– After the Exercise (immediately after and again
2-6 hours later)
The Timing of Carbohydrate Intake for
Exhaustive Athletic Performance
Timing and Amount of
Intake
4 hours prior
4 gm/kg
1.82 gm/lb
68 Kg Exchange List Pattern
68 Kg Food and Beverage Options for Exchange List Patterns
10 starch
5 fruit
3 other carbohydrates
2 hours prior
2 gm/kg
0.91 gm/lb
6 starch
3 fruit
5-10 minutes prior
0.5-1 gm/kg
0.23-0.45 gm/lb
During
60 gm/hr
2-4 other carbohydrates
Immediately after
Carbs: 1.65 gm/kg or 0.75
gm/lb
Protein: 0.55 gm/kg or
0.25 gm/lb
2-6 hours after
Carbs: 1.65 gm/kg or 0.75
gm/lb
Protein: 0.55 gm/kg or
0.25 gm/lb
7 starches, 3 meats Or
2 milk, 2 fruit, 4 starches, 2
meats Or
1 milk, 2 fruit, 4 starches, 3
meat
5 starches, 2.5 vegetables, 3
meats, 2 fruits or similar to
immediately after meal
2 cups pasta (90 g)
1 bagel (60 g)
1 cup juice (45 g)
1 cup fat-free frozen yogurt (45 g)
1 large banana (30 g)
(270 g total)
1.33 cups pasta (60 g)
2 slices of bread (30 g)
1 cup juice (45 g)
(135 g total)
1-2 low-fat sport bars (2 ounce size) or the equivalent of 2-4
tablespoons of sugar
(34-68 g total)
A six percent glucose electrolyte replacement solution provides
about 15 grams of carbohydrate per cup of fluid
(1 tablespoon of sugar and ¼ teaspoon of salt per one cup water,
drink 2-4 cups per hour)
2 cups low-fat milk (24 g carbs, 16 g protein)
2 cup ready-to-eat cereal (60 g carbs, 12 g protein)
4 tablespoons raisins (30 g carbs)
2 egg whites (14 g protein)
(114 grams of carbohydrate and 42 grams of protein total)
3 ounces chicken (21 g protein)
1 large baked potato (60 g carbs, 12 g protein)
1.25 cups cooked broccoli (12 g carbs, 5 g protein)
1 small roll (15 g carbs)
1 large pear (30 g carbs)
(117 grams of carbohydrate and 38 grams of protein)
2-4 other carbohydrates
exchanges/hour
Recovery Nutrition after Exercise
• Muscle glycogen repletion begins
immediately after the exercise and
prepares the energy stores for the next
workout!
• Consuming meals that provide the
combination of carbohydrate and
protein at a three gram to one gram
ratio promotes muscle glycogen
repletion
Proteins
• Athletes require more protein to stay in
nitrogen balance as compared to individuals
who are meeting their DRI for physical activity
• The range is 1.2 to 1.6 grams of protein per
kilogram of body weight
• To support lean body mass gains, a strenuous
weight-lifting program, 1.6 grams of protein
per kilogram of body weight and a positive
energy balance of 200 Calories is needed
• High quality or the complement equivalent is
needed for 2/3 of the protein consumed
Fats
• The dietary fat recommendations made to the
athlete are the same that support health and
meet the DRIs
• Consume low-fat foods prior to exercise and a
low-fat (20-25% of Calories) diet in general
• Adding MUFAs may be the best choice of fats
if weight gain is desired
• MCT have been touted to be useful during
exercise, but not proven, however, they are
useful for malabsorption syndromes due to
their direct absorption into the blood stream
Thermal Regulation and
Hydration
• The ability to keep the body cooled during
exercise is key to exercise capacity and
avoiding injury.
• A lot of heat is generated in the body due
to the inefficiencies of energy transfer to
make ATP.
• Sweating creates the evaporative cooling
system employed during exercise to keep
the core body temperature in a functional
range.
Understanding and Controlling
Body Temperature
• The core body temperature rises during
exercise
• If the core body temperature >104oF, exercise
capacity diminishes and risk of thermal injury
increases
• Fluid, salt, and other components are lost in
sweat during exercise – about a liter of fluid
per hour of exercise, and 2.6 grams of salt per
liter
• Salt (NaCl) is 40% sodium, ½ t salt replaces
the sodium lost in 1 hour of vigorous exercise
Dehydration to Hydration,
Part 1
• The fluid lost in sweat comes from the
blood stream
• The plasma volume is the fluid reserve
for sweat
• This is why there is such large
deterioration in aerobic exercise
capacity due to dehydration
Dehydration to Hydration,
Part 2
• The sensation of thirst signifies 2%
dehydration, cardiovascular and aerobic
function is reduced.
• 5% dehydration, serious thermal injury risk.
• The body can absorb 1 liter of fluid per hour.
• Replacing fluids (cool, dilute, small, and
frequent amounts) during strenuous
exercise is important:
– 1 cup at 41oF, every 10-15 minutes
– Drink without thirst to avoid dehydration
Hydration Health and
Dehydration Demise
Importance of hydration
during exercise
 Optimizes muscle strength
 Optimizes aerobic capacity
 Prevents thermal injury
which include dizziness,
cramping, fainting, heat
exhaustion and heat stroke
 Maintains a pool of fluid to
draw upon for sweat loss is
the blood stream.
 Avoids stress to the
cardiovascular system,
which is affected
dramatically by fluid losses.
Cardiovascular demise
during dehydration
 Plasma volume decreases
 Osmolarity of the blood
increases
 Blood pressure goes down.
 Constriction of the blood
vessels
 Increase in heart rate
 Decrease in heart filling
 Decrease in cardiac output
 Decreased sweating
 Increase in core body
temperature
Some
Summary Points, Part 1
• Fuel and hydration management are so
influential on exercise capacity.
• As the intensity of the exercise increases, so
does the percent of carbohydrate used to
produce ATP.
• Carbohydrate stores in the body are limited.
• Dietary carbohydrate intake before, during,
and after exhaustive exercise can enhance
exercise performance.
• A combination of carbohydrate and protein
(3:1 ratio) consumed after exercise can
support muscle glycogen repletion.
Some
Summary Points, Part 2
• The protein needs of most competitive
athletes range between 1.2 to 1.6 grams of
protein per kilogram of body weight per day.
• A low fat diet that provides all of the
essential fatty acids in adequate amounts
can support most athletic endeavors.
• Adequate hydration from fluid and salt intake
is important for aerobic performance and
avoiding thermal injury.
References for this presentation are the same as those for this topic found in module 4 of the textbook